Testing device for ignition systems.



9 H. B. L 0. G. HOLMES.

TESTlNG DEVICE FOR iGNlTlON SYSTEMS.

APPLICATION FILED JAN. 21.1918.

lu/venten Ciara, H.E.Hmlma5 ana mar' E I'nlmas PatQntd Jan. 14, 19.19.

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`C. H. B. 690. G. HOLMES. 'TESTING DEVICE FOR lNlloNksYsTEMs.

APPLICATION 'HLED 1AN.21.19IB.

1,290,995. Patented Jan.14,1919.

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CLARA HERMINA BORGESON HOLMES .AND OSCAR GOTHARD HOLMES, -0F CLEVELA'NI),

OHIO.

TESTING DEVICE FOR IGNITION SYSTEMS.

Application ledjanuary 21, 1918.

To all whom t may concern:

Be it known that we, CLARA H. B. HOLMES and OSCAR G. HOLMES, citizens orA the United States, and residents of Cleveland in the county of Cuyahoga and State oi Ohio, have invented certain new and useful Improvements in Testing Devices for Ignition Syst-ems, of which the following is a specification.

ur present invention relates to a testing device for ignition systems, and more particularly to a device of this character with which tests can be made to determine the efficiency of generating mechanism or of spark plugs when subjected to substantially the same conditions as are encountered when the parts are installed as the ignition system for an internal combustion engine.

It has been found in testing magneto and battery ignition systems that they will often show what seems to be a good spark when tried in the open, but will not fire and act eiliciently when under compress .n charge. Therefore, it is the principal purpose of our inventionvto provide a test device or s stem which can be used to test spark plugs as installed in an ignition circuit with theV spark plug fitted to a closed container in which any desired pressure can be obtained, and which closed container or such -eon` struction that the action of the spark plug can be watched.

A further object resides in so constructing the device that it can be applied to test a system including one or more spark plugs, and can be connected in circuit wiring already installed for the ignition system.

Another vobj ect resides in providing means by which any desired pressure can be attained in the chambers to which the spark plugs are iitted, and in associating with the same pressure indicating means to thus permit accurate gaging of the pressure under which the system is tested.

Further objects of our invention will appear in the following detailed description, taken in connection with the accompanying drawings, forming a part of this specification, and in which drawings:

Figure l is a -view in elevation of a device constructed ai'ter the manner of our inconnections diagrammatically illustrated.

Fig. 2 is atransverse vertical sectional View taken on the line 22 of Fig. l.

Specification of Letters Patent.

Patented aan. ia, reis. serial No. 213,020.

Fig. 3 is a fragmentary sectional View, illustrating the fitting of a bushing to adapt the device for use with spark plugs of difA ferent sizes.

in the drawings, refer to similar A designates a where similar characters parts throughout the views. base member which is of metal, and B is a top member, also of metal. The base and top members A-and B are made as strips oit' suitable length and are adapted to be mounted in parallel disposition as shown in Fig. l. A plurality of tubular members C, which are of glass or other suit-able transparent material are mounted between the base and top'members A and B and these members are drawn down against the ends of the tubular members C by the clamp bolts D. A pressure pump E, which'can be of the hand or mechanically operated type, has a compressed air supply pipe l? leading therefrom and extending substantially parallel with the top member of the tubular members so that the pressure of iiuid through operation of the pump E is at all times dcterminable. n Fig. l of the drawings, we have illustrated the device of our invention connected in an ignition system such as would ordinarily be used for an internal combustion engine, and as is shown the system includes a Generator I, a breaker J, and a distributer l with suitable circuit wiring.

As has been stated, the tubular members C are fitted between the base and top inembers, and to insure that the tubular members will be maintained in the proper positions at all times, the base member A is counter;- bored, as indicated at l, while thetop memL bei' B is correspondingly counter-bored as at 2, it being understood that the recesses thus formed are so proportioned that lthe tubular members C willsubstantially lit and lill out the same when their ends areplaced therein. To establish a fluid tight connection between the tubular members and top members, and thus compartment within each members, the packing rings 3 and l are mounted in the counter-bored recesses of the base and top members to have the ends of and the base the tubular members C bear thereagainst, and then as the clamp nuts 3 are tightened upon the clamp bolts D, the base' and top members A and B are properly clamped B has a plurality of screw-threaded openf ings 6 provided therethrough and so spaced that 'each of these vopenings is substantially centered Within one of the tubular members C, and thus a spark plug, as indicated at L, can be tted to have the sparking ter minals thereof Within the air tight compare ment, and at the same time these sparking terminals Will be clearly visible through the transparent member C.v As the device maybe used to test systems including spark plugs of different sizes, it is preferably that the screw-threaded openings 6 be made to take a spark plug of maximum size, and that bushings M, as shown in Fig. 3, be provided to adapty the device for use with spark plugs of smaller sizes. vOne or more sets ci' the bushings M might be provided, and it will of. course be appreciated that thev screw threaded central bore 7 Will be made of a size and threaded in a manner to receive smaller spark plugs than 'might tit within also vbe understood that the opening 6, of the top member B. That the bushings may be readily litted in place and removed, the polygonal head portions 8 are provided, and it will of course be underd stood that Where necessary or desirable` packing Washers 9 mightbe employed to in sure an absolutely tight connection ofl each bushing. This position of the bushings adapts the device for use Where spark plugs are of large or small size, and as it is prelierably that some six or lmore of the trans parent members C be mounted between the base and top bars A and B, to thus adapt the device for use upon the ignition system of an engine having a number'of cylinders, it will lmade for cutting out or disconnecting cer tain of the branch pipes Gr from the compressed air supply pipe F when the com vpartments to which they lead are not in use.

as .otherwise lair supplied through these 'pipes would escape through the openings 6 and in consequence, 1t would not be possible to `obtain the desired fluid,r pressure Within the chambers to which active spark plugs are tted. With this in mind, the cut oft valves 10, 11, 12, 13 and, 14, are connected in ce1 tain of the branch pipes G. 1n this connecprovision must be,

to test a system including a maximum number of spark plugs for Which the device is constructed, and in the present illustration, We have shown the connection which is es tablished in testing the spark plugs and the ignition system of a four cylinder engine. As six compression chambers are embraced Within the device as here illustrated, the valves 13 and 14 are closed so that communication is established and maintained from the compression air supply pipe F to but four of the compression chambers, and then the spark plugs 15, 16, 17 and 18, are iitted to and set Within the threaded openings 6 Which open into those compression chambers still connected With the compressed air supply pipe. The usual circuit connections from the distributer to the spark plugs are maintained, and a part of the frame structure including the base and top members is ground Wire from ther generator is connected therewith. When this connection has been established, the pump E is operated to obtain any desired fluid pressure Within the compression chambers to which the spark plugs are fitted, which pressure Will be indicated bythe gage H, and then by reason of the fact that the tubular members C are of a transparent material, the action of the spark plugs under any given pressure or under varying'pressures can be accurately determined. As under some circumstances, it may be desired to reduce the pressure and observe the action under these conditions, and again the pressure must be partially reduced before the spark plugs are removed, an outlet valve 19, which might Well be of the three-Way type is connected in the pipe F where the same leads from the pump E. lt Will of course be understood that when the pressure is being raised in the compression chambers, this valve 19 Will be set to establish a straight passage through the pipe F and that the pipe Will be substantially continuous, but when the pressure is to be reduced, the valve is set to establish communication from the several branch pipes through the connected length of the pipe F and then through the exhaust opening 20 of the valve.

While We have herein described-the device as particularly adapted for use in testing ,grounded on the engine structure or the preciated that the device will at the same p time, give the user an opportunity to determine the relative intensity of the spark of the several spank plugsto accurately adjust i the Width of the spark gap and then observe the effect of such adjustment, and to deter mine Whether the circuit connections are properly made to secure sequential tiring in the use of the engine With-Which the ignition system is installed.

Changes in details may be made without departing fromvthe spirit or scope-oi?` our invention; but

We claim:

1. A spark plug. and ignition tester including base and top members made in the form of elongated bars adapted to be mounted in parallel relation, said base and top members `being provided with counter-bore openings on adjacent faces thereof, tubular members of,transparentmaterial fitted be tween said base and top members with their ends in the counter-bores of said members, clamp bolts by which the base and top members are tightened against the tubular members to form fluid tight compression chambers, said top member having openings therethrougltf for the reception ofspark plugs to dispose the sparking terminals of said plugs within the compression chambers, .a compressed air supply pipe, branch pipes extending from 'the air supply pipe to each of the several compression chambers, cut o't valves connected in several of said 4branch pipes, a pressure gage connected with one of the compression chambers, a pump by which air is supplied to the main pipe, and

relieve the fluid bers.

2. A spark and ignition tester including aa valve connected in said pipe to reduce and pressure Within the champair of rectangular metal plates, a plurality of transparent cylinders supported between I said plates, and in fluid tight connection therewith, the uppermost of said plates pro vided with openings adapted to receive a spark plug with the sparking terminals within the transparent cylinders, a pipe for supplying air under pressure having a plurality of branch pipes entering said transparent cylinders through said top plate, and means whereby the inlet or exhaust of fluid under pressure into or from said transparent cylinders independently of each other or in unison may be accomplished.

3. A spark plug and ignition tester including a pair of .rectangular parallel metal plates provided vwith counter bores in their facing surfaces, transparent cylinders having theirends fitting in said counter bores, packing washers between the ends of the cylinders and the plates for forming a fluid tight joint between the cylinders andplates, one of said plates provided with openings adapted to receive spark plugs with the sparking terminals within the chambers of the transparent cylinders, a pipe for supplying fluid under pressure, branch pipes carried by said first pipe and extending .into said cylinders, and means for controlling the inlet into or exhaust of fluid under lpressure to 0r from said cylinders whereby any. one of the cylinders may be charged or relieved independently of the others. 

